This year Shelter celebrates its 50th anniversary and the milestone has sparked mixed emotions. I can be proud that we have tried our hardest to improve housing in England, often with notable successes. But I’m also sad that we are still here having to do so.

The Housing and Planning Act only crystallised this tension. We, with many others, did our utmost to fight the erosion of genuinely affordable housing – and won some vital improvements to the safety of the private rented sector. But I am bitterly disappointed at the overall result. Starter homes will cannibalise genuinely affordable homes and much needed council homes will be sold off in the areas that need them most.

Could we have done more to ensure that the people we’re here to help are well housed? The government has been forced into retreat over numerous issues over the past year: tax credits, academies, fox hunting, the Human Rights Act, the Transatlantic Trade and Investment Partnership (TTIP), the list goes on. And yet, despite near unprecedented opposition in the Lords, they were resolute in their vision for housing.

Shelter research showed that starter homes will be unaffordable to ordinary families. But the government never seemed to meaningfully fear a backlash.

Why, when the government finally flinched from taking tax credits away from people and was forced to delay reform of disability benefits, did it feel empowered to push through attacks on social housing?

I suspect at the heart of it was a calculation that there was a lack of passionate public support and therefore no political pain to be had in dismantling social housing.

Research by the Fabian Society (pdf) shows that the public are supportive of the principle of social housing – but crucially, they are less likely to see it as something for them. The majority of people see it as a social service for other people, not the answer to their own need for affordable housing or security. It’s nice to have, but as an abstract thing.

The same research shows real stigma attached to social housing – half of respondents thought people living in social housing were stigmatised. In this context, is it really surprising that more people didn’t stand up to demand the government build more genuinely affordable social housing? Families on low- to middle-incomes are crying out for a government to address their housing needs – but they’re not demanding social housing as part of the answer.

If we are all going to stem the tide of increasing costs and declining supply, then we have to really understand why the government was so supremely self-confident in its plans to replace genuinely affordable housing with options solely suitable for affluent first-time buyers.

There will be many competing hypotheses, some providing false comfort, others requiring deep and often troubling thinking. But it’s a debate we welcome – and one that’s essential if we want more people to be better housed in the next 50 years.